1. Field of the Invention
The present invention relates to a method of manufacturing a semiconductor device that includes an optical grating having a periodic corrugation pattern.
2. Related Prior Art
It is well known in the field of micro-processing technologies that a dual light flux interferential exposure method and an electron beam exposure method have mainly be used for forming an optical grating in a semiconductor device. On the other hand, an optical nano-imprint technique has recently been developed as a new method for forming a fine pattern.
A technique known as such a nano-imprint technology is a method of forming a fine pattern as disclosed in Japanese Patent Application Publication No. 2000-323461, for example. According to this conventional method of forming a fine pattern, a mold (nano-stamper) for nano-imprint is formed on a mold board having a mark for positional reference, and a mask layer is formed on the semiconductor substrate. By pressing a nano-stamper onto this mask layer, a fine pattern formed on the nano-stamper is transferred onto the mask layer. Thereafter, by performing the RIE etching using the mask layer, the fine pattern is formed on the surface of the semiconductor substrate.